The primary stability of a cementless stem varies between subjects as much as between activities

Alberto Pancanti, Marek Bernakiewicz, Marco Viceconti

Research output: Contribution to journalArticle

66 Citations (Scopus)

Abstract

The rehabilitation program adopted immediately after a cementless total hip replacement is a very important factor, because of the known relationship between osseointegration and implant micromotion. The present study was aimed to evaluate which type of task is the most critical in terms of bone-implant relative micromotion. Both inter-task and inter-subject variability were taken into account to verify if the movement strategy could be determinant on this assessment. A previously validated finite element model was used to predict the peak total micromovements over the entire bone-implant contact surface in four different patients, performing nine different tasks, using published data on joint forces recorded by instrumented hip prostheses. The results predicted by the various simulations suggest that while stair climbing is surely a critical task for primary stability, for some subjects other tasks may be as critical as stair climbing. From a variance analysis for simple crossover design on the predicted peak micromotion, the inter-subject variability had much more influence on the primary stability of cementless implant than the inter-task variability. Even if the results of Patient IBL, who was reported to have difficulties to perform any activities in a normal way, were excluded from the statistical analysis, the inter-subject variability remained still higher than the inter-task variability. The results obtained from simulations suggest that the strategy the hip replacement patient adopts to perform a given motor task, may be, for the implant stability, equally or even more critical than the type of motor task performed.

Original languageEnglish
Pages (from-to)777-785
Number of pages9
JournalJournal of Biomechanics
Volume36
Issue number6
DOIs
Publication statusPublished - Jun 1 2003

Fingerprint

Stairs
Bone
Hip prostheses
Osseointegration
Bone and Bones
Hip Prosthesis
Hip Replacement Arthroplasties
Patient rehabilitation
Cross-Over Studies
Hip
Statistical methods
Analysis of Variance
Rehabilitation
Stair Climbing

Keywords

  • Cementless fixation
  • Hip prosthesis
  • Primary stability
  • Rehabilitation
  • Task

ASJC Scopus subject areas

  • Orthopedics and Sports Medicine

Cite this

The primary stability of a cementless stem varies between subjects as much as between activities. / Pancanti, Alberto; Bernakiewicz, Marek; Viceconti, Marco.

In: Journal of Biomechanics, Vol. 36, No. 6, 01.06.2003, p. 777-785.

Research output: Contribution to journalArticle

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